// Copyright 2018 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package types

import "github.com/google/cel-go/common/types/ref"

var (
	// DynType singleton.
	DynType = NewTypeValue("dyn")
)

// IsDyn indicates whether the input ref.Val or ref.Type is equal to DynType.
func IsDyn(elem interface{}) bool {
	switch elem.(type) {
	case ref.Type:
		return elem == DynType
	case ref.Val:
		return IsDyn(elem.(ref.Val).Type())
	}
	return false
}
